English

Coincidence free certification and quantification of spatial entanglement with stimulated parametric down conversion

Quantum Physics 2026-07-27 v1 Optics

Abstract

Using stimulated emission, a photon pair source can be characterized by seeding the signal mode with a bright classical beam and measuring the stimulated idler field, thus replacing two-photon coincidence counting with classical intensity detection. We apply this approach to the continuous transverse spatial degrees of freedom of a down conversion source and show that it is possible to certify spatial entanglement with only intensity measurements. We demonstrate this capability through variance-based entanglement and steering witnesses, as well as the Fedorov ratio. This method is useful for studying entanglement properties of photon pair sources in conditions where alignment and photon counting measurements are difficult and time-consuming.

Cite

@article{arxiv.2607.24718,
  title  = {Coincidence free certification and quantification of spatial entanglement with stimulated parametric down conversion},
  author = {M. G. Damaceno and G. H. dos Santos and N. Rubiano da Silva and S. P. Walborn and P. H. Souto Ribeiro},
  journal= {arXiv preprint arXiv:2607.24718},
  year   = {2026}
}

Comments

8 pages, 8 figures